#include<fstream>
#include<vector>
#define dim 100007

using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");
int rmq[20][3*dim],x,y,i,q,k,n,j;
vector<int>G[dim];
int eul[3*dim],ap[dim],p[3*dim];
void swap(int a,int b){
    int aux=a;
    a=b;
    b=aux;
}
void  dfs (int nod ){

    eul[++k]=nod;
    ap[nod]=k;
    for(int i=0;i<G[nod].size();++i ){



        int fiu=G[nod][i];

            dfs(fiu);
            eul[++k]=nod;
    }
}
inline int minim(int a,int b){
    if(a<b)
        return a;
    return b;
}
int main () {
    f>>n>>q;

    for(i=1;i<n;++i){
        f>>x;
        G[x].push_back(i+1);
    }

    dfs(1);
    for(i=2;i<=3*dim;++i){
        p[i]=p[i/2]+1;
    }
    for(i=1;i<=k;++i){
        rmq[0][i]=eul[i];
    }

    for(i=1;(1<<i)<=k;++i) {

        for(j=1;j+(1<<i)-1<=k;++j){

            rmq[i][j]=minim(rmq[i-1][j],rmq[i-1][j+(1<<(i-1))]);
        }

    }
    for(i=1;i<=q;++i) {
        f>>x>>y;
        x=ap[x];
        y=ap[y];

        if(x>y)
            swap(x,y);
        int H=p[y-x+1];
        g<<minim(rmq[H][x],rmq[H][y-(1<<H)+1])<<"\n";
    }
    return 0;
}